July 2011

July 2011

DO YOU HAVE A GREEN THUMB?

I recently had a conversation with a friend who admits he “is not into growing plants”. He commented, “I guess I don’t have a green thumb.” And then he almost defined what a “green thumb” is in his next remark. He said, “I guess you really need to have an interest in something to be successful at it.”

As long ago as I can remember, I have always had an interest in growing plants. If I have a green thumb, where and when did I get it? Did my years of experience and education give me a green thumb?

Most of my horticultural education and reading have been focused on the scientific or “how to” aspects of plants. Most of what I write is about practical aspects of gardening. For years I never stopped to analyze (sounds scientific, doesn’t it?) the impact of feelings and emotions on my success in gardening. In fact, my friends told me that I was a pretty unemotional person.

Looking back I realize that I was hiding a lot of my feelings and emotions, even from myself. Now I take time to understand the emotional side of all aspects of life. I now enjoy gardening more than I ever have.

So if you are a struggling gardener, realize that how you feel about gardening is just as important as what you know about gardening. Stop thinking about gardening as work that you have to get done. Think of it as beauty you are trying to create. There is nothing more satisfying than creating something beautiful.

REMOVE SPROUTS ON RECENTLY PRUNED TREES

Early July is a critical time to remove those fast growing vertical sprouts that occur after trees are pruned in the fall, winter or early spring. This is particularly true for fruit trees which have been heavily thinned so light can reach the lower fruiting branches. Sprouts can be quickly and easily snapped off with your fingers when they are soft and flexible. Snapping is preferable to cutting, because it removes tissue which can regrow another water sprout, sometimes in the same growing season. If you wait until fall or winter to cut those sprouts, new ones will grow to replace them next spring. Stop the sprout cycle now. And if you do happen to have more new water sprouts later, snap them off while they are young and soft.

Sprouts growing on the base of the trunk can also be snapped off while young. If they are too big to snap, remove with a knife, sharp shovel or other tool as close to the trunk as possible. Once removed, the base of the trunk can be sprayed with a growth inhibitor called “sucker stopper” or “sprout inhibitor” containing NAA. This is a natural growth hormone which will prevent sprout regrowth for about 3 months. It is available from most full service nurseries and garden stores or can be ordered on line.

Some trees produce sprouts from underground roots away from the tree trunk. These can be killed with lawn weed killer without damaging the tree. Do not use weed killer on sprouts attached to the trunk, because it could damage the tree.

IS BAGGED PLANTING MIX THE BEST WAY TO IMPROVE SOIL?

Gardeners are increasing their use of bagged “planting mixes” to add to garden soil for planting vegetables and flowers. These planting mixes are different than typical “potting soil” used for container planting. Most gardeners have had good results using these mixes, so their sales volume continues to increase.

Some gardeners place a layer of mix several inches deep on top of their regular soil. Most incorporate the planting mix using a hoe, shovel, or spading fork. Mixing them with regular soil is a better choice. It avoids the creation of a distinct layer which can disrupt water movement through the soil.

These mixes contain a variable mixture of ingredients. Even the same brand of mix will vary from month to month or year to year. The most valuable ingredients in the mixes are organic materials such as peat moss, bark dust and compost. Some contain vermiculite or perlite, which are common ingredients in potting soils. Most also contain some garden soil and sand. Most also contain fertilizer with the trend toward slow release or timed release coated fertilizer.

Mixing, bagging and shipping adds to the cost of these planting mixes. Are they really worth the cost? They may be a reasonable choice in small areas or for the novice gardener who gets good results from a single additive. However, most gardeners would get equally good (or better) results using a different approach.

Your own compost, made primarily from grass clippings and leaves, is the cheapest source of organic matter. Even uncomposted grass clippings can be mixed directly into the soil with good results.

In our area bark dust is the cheapest organic material you can purchase. It is readily available in bulk (delivered to your driveway) which is several times cheaper than bagged products. Adding half as much compost or fine bark dust would give the same or more organic matter as the full amount of soil mixes. Add some organic or slow release fertilizer and you have equal or better results at a much lower cost.

BEST WAY TO IRRIGATE

July and August are the highest water use times of the year. We have a combination of warmer days, hotter temperatures and less rainfall. All this adds up to a higher evapotranspiration rate. Evapotranspiration is a combination of evaporation of moisture from the soil and transpiration from plant leaves. Leaves emit water vapor from their leaf pores for cooling.

The best way to irrigate you lawn and other landscape areas is to apply enough water to reach the full depth of the root system. You can develop a deep root system by allowing the soil to dry between irrigations. It requires at least 1/3 inch of moisture to reach six inches deep. A 10 minute irrigation will only wet the top inch or two of soil. It is better to water for 20 or 30 minutes and then wait 3 or 4 days between irrigations.

You can determine how long it takes to deliver 1/3 to 1/2 inch of water using your sprinklers by placing shallow cans such as tuna fish cans on the lawn. Water for a specific interval such as 30 minutes and then measure the accumulated water with a ruler.

When you place a can in brown spots and another in nearby green areas, you will probably find that they are not receiving the same amount of water. You may be able to adjust your sprinklers so the water distribution is more uniform.

Raising the mowing height will also help in keeping your lawn green. Years ago I observed two different experiments on lawn mowing height. Both showed that the amount and depth of grass roots is in direct proportion to their leaf surface area. Lawns mowed at 2 inches will have twice the root system as lawns mowed at 1 inch. The greater root system makes the grass more efficient in extracting water from the soil.

“Walking Encyclopedia of Horticulture”

Allen Wilson is frequently referred to as the “Walking Encyclopedia of Horticulture” due to his extensive education, experience and knowledge of all aspects of horticulture. He has the capability of solving almost any landscape, gardening, arboriculture or horticulture problem on the spot. Call for a free consultation.